Interestingly, Poser doesn't use external normals - it always creats it's own. If raydream allows it don't even export them cause they just waste file space.
If you have a hole it's probably an empty polygon. It's been a long time since I've used RDS but I think there's a Fill Polygon command that should fix this.
If it's black or has some other weirdness sounds like a fliped polygon. In this case you need to do an Empty Polygon then the Fill Polygon. But if you have a lot of "bad" polygons this can be a real nightmare!
I don't have UVM Pro (still wating on the Mac version) but it has a lot of features for fixing problem polygons. Certainly worth giving the demo a try.
HTH - Dan